Spark plug



`June 2s, 1938. A. A.- ST. JQHN 2,122,015

` 'SPARK PLUG I Filed July' 10, 1936 2 Sheets-Sheet 2- al; Elflmlm-L I I l l f Il /wy/@JA szJa/zm.

A .l Attorneys Patented June 28, 1938 UNITED STAT-as eraan PLUG Alfred 'A'.si. Jaim, Manchester, N. n. Application my 1o, 193s, sensi No. cas-14 v s claims. (cLiza--ism My invention relates generally to a spark-plug,

and particularly to a multiple sparking point` spark plug, enabling single, dual, and multiple w ignition o f a charge in the cylinder of an internal combustion engine, and an important object of my invention Vis to provide a spark plug of this character which -is readily adjustablev for single, dual, and multiple ignition, and which is simple and inexpensive in structure. l0 Other important objects of my invention will be, apparent from a reading of the following de script-ion taken in connection with the drawings,

wherein for purposes of illustration I have shown preferred` embodiments of my invention. In the drawings:-

Figure 1 is a general transverse vertical sectional view taken through the embodiment.

Figure 2 is a top plan -view of Figure 1 with the inverted U-shaped support remoted.

Figure 3 is a bottom plan view of Figure l.

.Figure 6 is a transverse vertical sectional view taken through Figure 5.

Figure 7 is a horizontal sectional view taken through the yupper part of Figure 6 and looking upwardly.

Figure 8 is a perspective view of the brush.

' 35 Referring in detail to the drawings, the numeral 5 generally designates the embodiment of the invention which comprises a. spark plug shell i of generallyconventional type which involves the exteriorly threaded lower end for engaging y the spark plug hole of the engine, with the engine block engaging ilange 8 thereabove, and above the flange 8 the wrench receiving ange 8.

In accordance with the present'invention the bore of the shell 8 is specially formed to receive 45 the special porcelain or other insulating material 55 I5; and threaded into the upper end of the bore is the crore'- locking nut I6` which engages the threadsY i5 and also the top of the triangular cross section shown at Ilot the core. whereby the core is locked in place in the shell 6. It is to be observed thatthe core i0 does not riseabove the i5v shell 6 to as great a height as is conventional.v

The core is provided on itsupper end with a reduced portion I1 which receives the dielectric cap I8 which seats on the reduced portion and flush with the exterior of the core. lo

Depending through the middle of the cap i8 isthe binding post i9 which has its lower end anchored as indicated by the numeral `2il in the top of the core, and has its upper end threaded as indicated-by the numeral 2l to receive the bindl5 ing post nut 22 which clamps the spark plug wire c lip or connector to my spark plug.

, Close tothe exterior of the core I0 is a series of equally circumferentially spaced longitudinal electrodes' 23 which have enlarged upper'ends 2l 20 provided with cupped portions '25, the ends 2l being ilush with theupper end oi the core; and the lower ends of the electrodes being exposed below the bottom oi' the core and on a level with the depending portion 28 which has radial slots 21 25 therein which open through the sides of the electrodes and iormsparklng chambers in such a way that adjacent electrodes are isolated from each other so that there can be no jumping across of a. spark between adjacent or opposite *elec- 30 trodes. w A The lower end of the shell 6 is disposed on a level with the bottom of the core and has de pending therefrom the L-shaped sparking points 28.which have their horizontal armsradially in` 35 wardly directed rand properly spaced from the lower ends of lthe electrodes 23, as clearly shown in` Figure 3. l

Pivoted 'on the binding post I9 are the inner ends of one ormore contact arms 29, 30 which 40 have contact buttons on the underside of their outerends to seat in the depressions-25 in the upper ends of the selected electrodes 23. With the spring contact a'rms 29 and 30 arranged `as shown in Figure 2, dual ignition is conditioned. Any number of arms may be utilized up to the `full total number of the electrodes infthe core; or

only one of the contact arms may be utilized to obtain single ignition.

A helical spring 3| interposed. between the cap 50 Y I8 and the tops of the iarms 29 and 30retain the arms in forcible vcontact withthe upper ends of the electrodes 23. v

The embodiment of theinvention shownl in Figures 5, 6, 7, and 8 of the drawings has the same -55 tively by a' convex portion 34 on the outer exshell, core, electrodes, and the same core locking nut, as well as th same formations and arrangements of the elec rodes and core and shell at the lower end of these. Therefore corresponding. numerals, primed, have been applied to designate these similar parts in Figures 5, 6, '1, and 8 of the drawings.

In addition to the parts mentioned above the present embodiment has iianges 32 on the electrodes 23' embedded in the material ot the core to prevent shifting ofthe electrodes.

The tops 33 of the electrodes are here convex instead of concave and they are engaged selectremity of the spring arm 35 which extends radially from the collar 36 which turns on the binding post 2li'. In `the present instance anchoring flanges 3l are formed on the lower part of the 39 which is rotatable on the binding post I9' and may rest on the upper end of the nut I3'. Simply turning the dielectric cap 33 rings the contact.-

arm 35 into engagement with the selected one of the electrodes 23. l

On the threaded upper end of the binding post a suitable spark plug Vwire connection 4l is threaded and holds the cap 39 in place.

Although I have shown and described herein preferred embodiments oi?A my invention. it is to be deilnitely understood that I do not desire to limit the application of the invention thereto, and any change or changes may be made in the materials, and in the structure and arrangement of the parts. within the spirit of the invention and the scope of the subjoinedclaims.

What is claimed is:-

l. A spark plug of the character described comprising a spark plug shell having a plurality of circumferentially spaced sparking points on its lower end, a core mounted in the shell and having a plurality of circumferentially spaced electrodes extending longitudinally therethrough, said core being formed with protective openings lin the lower end thereof in which said electrodes project adjacent corresponding ones oi' the sparking points, and adjustable contact means on the upper end of the corein' commotion with a binding post for selectively energizing diii'erent ones of the electrodes simultaneously.

2. A spark plug of the character described comprising a spark plug shell having a plurality of circumferentlally spaced sparking points on its lower end, a core mounted in the shell and having a plurality of circumferentiallyspaced electrodes extending longitudinally therethrough, said core being formed with protective openings in the lower end thereof in whichA said electrodes project adjacentv corresponding ones oi the sparking points, adjustable contact means on the upper end of the core in conjunction with a binding post for selectively energizing different ones-of the electrodes simultaneously, said adjustablecontact means comprising a dielectric rotatable cap on the upper end of said core. and a spring brush fixed thereto for selectively engaging the upper ends of the electrodes. Y

3. A spark plug oi the character described coinprising a spark plug shell having a plurality of circumferentially spaced sparking points on its lower end; a core mounted in the shell and having extending longitudinali fastened rigidly by suitable A enamoro a plurality of circumierentialiy spaced electrodes y therethrough, the lower end o! said core being formed with protective openings.' in which said electrodes project adjacent corresponding ones of the sparking points, and adjustable contact means on the upper end of the core in conjunction with a binding post for selectively energizing diiierent ones ofthe.

electrodes simultaneously, said adjustable contact means comprising swingable spring arms pivoted in the axis of said core and selectively engageable with dierent ones of .the upper ends of said electrodes simultaneously.

4. A spark plug of .the class described comprising a spark plug shell having a plurality of circumierentially spaced integral L-shaped sparking points on its lower end, acore mounted in the shell and provided with a plurality of circumferentially spaced electrodes extending longitudinally therethrough, the electrodes being wholly spaced radially inwards oi the peripheral outer surface-o! said core and having the upper and lower ends exposed throughthe'corresponding ends of said core, the lower endsoi.' said electrodes being cooperable with adjacent sparking POints, a binding post operatively associated with the lupper 'end of said core, and adjustable contact` means on the upper end of the core cooperable with the binding post, said contact means including a rotary arm, said arm being disposed radially with respect to the adjacent end of the core, and

'having its outer end terminating within the di- `lower end ot the core for coaction with said contact points, the upper ends of said electrodes terminating ilush with the upper end of the core,

a binding post secured centrally to and rising from the upper end of said core, a retention nut on said binding post, a protective cap of insulation material surrounding the binding post and interposed between the adjacent end of the shell and nut, and a radial conductive arm swingable ssr on the axis o! said binding post and attached to l said cap for rotation therewith. the outer end of said arm being resilient and terminating within the limits of the diameter of the adjacent end of the core and being selectively engageable with the adjacent ends of said electrodes.

6. A spark plug o! the class described comprising a shell, a 'core mounted in said shell, a plurality of electrodes extending longitudinally through said core and exposed at their upper and lower ends, a binding post mounted on top ot said core, said binding post including clamping nut, a pair o! duplicate selectively and collectively operable conductive arms pivotally attached at corresponding inner ends to said binding post, the

Amann A. s'r. JOHN. 

